feat: initial project setup

- FastAPI backend (Python 3.12, uv)
- React 19 + TypeScript + Vite frontend
- Devcontainer with Node 22, Python 3.12, uv, opencode
- Basic app structure and project docs

README.md

@@ -0,0 +1,17 @@
+# Kirche Einfach
+
+KI-gestützte Verwaltungsplattform für Kirche.
+
+## Stack
+
+- **Backend:** Python 3.12, FastAPI, Django, uv
+- **Frontend:** React 19, TypeScript, Vite
+- **Dev:** Devcontainer, opencode
+
+## Getting Started
+
+Open in VS Code → "Reopen in Container".
+
+Backend: `http://localhost:8000`
+Frontend: `http://localhost:3000`
+API Docs: `http://localhost:8000/api/docs`